A novel MoS2 quantum dots (QDs) decorated Z-scheme g-C3N4 nanosheet/N-doped carbon dots heterostructure photocatalyst for photocatalytic hydrogen evolution

et al. 2021

Small

Photocatalysis is a promising energy conversion and environmental restoration technology. The main focus of photocatalysis is the development and manufacture of highly efficient photocatalysts. Semiconductor‐based photocatalysis technology based on harnessing solar energy is considered as an attractive approach to solve the problems of global energy shortage and environmental pollution. Since 2009 pioneering work has been carried out on polymeric carbon nitride (PCN) for visible photocatalytic water splitting, thus PCN‐based photocatalysis has become a hot research topic, demanding significant research attention. This article reviews the physical and chemical properties, synthesis methods, and the methods to control the morphology, heteroatom doping, and construction of heterojunctions to improve the performance of PCN‐based photocatalysts in water splitting and nitrogen fixation. Through different design strategies, the photo‐generated electron‐hole pair separation efficiency of PCN materials can be effectively improved, thereby improving their photocatalytic performance. Finally, the challenges of PCN‐based photocatalysts in water splitting and nitrogen fixation applications are discussed herein. It is strongly believed that through different design strategies, efficient PCN‐based photocatalysts can be constructed for both water splitting and nitrogen reduction. These excellent modification strategies can be used as a guiding theory for photocatalytic reactions of other promising catalysts and further promote the development of photocatalysis.

Section: Photocatalytic Water Splittingmentioning

confidence: 99%

Polymeric Carbon Nitride‐Derived Photocatalysts for Water Splitting and Nitrogen Fixation

et al. 2021

Small

“… 31 , 32 Compared to the nanosheet counterpart, MoS 2 quantum dots (QDs) possess a higher surface area with more unsaturated terminal atoms, which are helpful in electrochemical reactions. 33 Therefore, MoS 2 QDs show a more interesting prospective as sensor materials. For example, MoS 2 QD-based sensors show a wide detection range (0.01–5.57 mM) and a low detection limit (1.90 μM) in the detection of H 2 O 2 .…”

Section: Introductionmentioning

confidence: 99%

Anchoring Metallic MoS₂ Quantum Dots over MWCNTs for Highly Sensitive Detection of Postharvest Fungicide in Traditional Chinese Medicines

et al. 2021

ACS Omega

Carbendazim, a very common contamination to the traditional Chinese medicines (TCMs), has posed serious threat to the environment and human health. However, sensitive and selective detection of carbendazim (MBC) in the TCMs is a big challenge for their complex chemical constituents. In this work, a 0D/1D nanohybrid was developed by anchoring 1T-phased MoS 2 quantum dots (QDs) over multiwall carbon nanotubes (MWCNTs) via a facile assembly method. High-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis (TGA) together with EIS reveal that the 1T-phased QDs can anchor over MWCNTs via van der Waals forces, and the anchoring improves the nanohybrid surface area and conductivity. Therefore, the electrochemical sensor fabricated based on the MoS 2 QDs@MWCNT nanohybrid shows excellent catalytic activity to MBC oxidation. Under optimized conditions, the sensor presents a linear voltammetry response to MBC concentration from 0.04 to 1.00 μmol•L −1 , a low detection limit of 2.6 × 10 −8 mol• L −1 , as well as high selectivity, good reproducibility, and long-term stability. Moreover, the sensor has been successfully employed to determine MBC in two typical TCMs and the obtained recoveries are in good accordance with the results achieved by HPLC, showing that the constructed sensor plate holds great practical application in MBC analysis with complex matrix.

“…For the local‐electric‐modification mechanisms, Z‐scheme heterojunction formed by carbon‐induced g‐C 3 N 4 system can intimate linkage with the conformation of in‐built electric field at heterogeneous interface. [ 87,88 ] Photogenerated electrons are directly migrated from the activated carbon to internal linked‐g‐C 3 N 4 for spatially enhancing photocatalytic charge carrier separation via interfacial band bending of Z‐scheme heterojunction. [ 89 ] Different from the ordinary typeII heterojunction photocatalysts, all‐solid‐state g‐C 3 N 4 ‐based Z‐scheme heterojunction has a particular interfacial charge gradient mechanism.…”

Section: Carbon‐induced Enhancement Mechanism In Photocatalytic Actionmentioning

confidence: 99%

“…For instance, Jiao et al. [ 88 ] reported that an adjacent N‐doped carbon dot (NCD) into g‐C 3 N 4 formed the Z‐scheme charge transfer mode through thermal polymerization and subsequent solvothermal method, which accelerated photocatalytic electrons separation in the process of electrostatic self‐assembly. The incorporation of NCDs into g‐C 3 N 4 remarkably reduced charge transfer barrier and shortened photocarrier transportation distance, thus highly imperative to enhance photocatalytic activity and stability for H 2 generation.…”

Section: Carbon‐induced Enhancement Mechanism In Photocatalytic Actionmentioning

confidence: 99%

Carbon–Graphitic Carbon Nitride Hybrids for Heterogeneous Photocatalysis

Cheng

et al. 2020

Small

103

Polymeric graphitic carbon nitride (g‐C3N4) and various carbon materials have experienced a renaissance as viable alternates in photocatalysis due to their captivating metal‐free features, favorable photoelectric properties, and economic adaptabilities. Although numerous efforts have focused on the integration of both materials with optimized photocatalytic performance in recent years, the direct parameters for this emerging enhancement are not fully summarized yet. Fully understanding the synergistic effects between g‐C3N4 and carbon materials on photocatalytic action is vital to further development of metal‐free semiconductors in future studies. Here, recent advances of carbon/g‐C3N4 hybrids on various photocatalytic applications are reviewed. The dominant governing factors by inducing carbon into g‐C3N4 photocatalysts with involving photocatalytic mechanism are highlighted. Five typical carbon‐induced enhancement effects are mainly discussed here, i.e., local electric modification, band structure tailoring, multiple charge carrier activation, chemical group functionalization, and abundant surface‐modified engineering. Photocatalytic performance of carbon‐induced g‐C3N4 photocatalysts for addressing directly both the renewable energy storage and environmental remediation is also summarized. Finally, perspectives and ongoing challenges encountered in the development of metal‐free carbon‐induced g‐C3N4 photocatalysts are presented.